condition mean min max ZT0-3 8.790622500000001 8.28026 9.300985 ZT4-7 7.54718 7.54718 7.54718 ZT8-11 7.20628 7.20628 7.20628 ZT12-15 0 0 0 ZT16-19 7.14815 7.14815 7.14815 ZT20-23 8.40608 8.40608 8.40608